Integrated circuits are nearing the
limitation of how small they can be constructed using conventional
means. Over the coming years new technologies will be needed for the
march towards ever smaller circuits and processors to continue.

In
November 2009, researchers developed new semiconducting
nanowires that will allow more transistors to be placed on future
computer chips. Scientists have now succeeded in creating a
transistor using a single molecule. The research team includes
scientists from Yale University and the Gwangju Institute of Science
and Technology in South Korea.

Researchers including Mark Reed
from Yale were able to demonstrate that a single benzene molecule
attached to gold contacts could
behave like a traditional silicon transistor. The energy states
of the molecules are able to be manipulated depending on the voltage
applied to the contracts. The manipulation of the energy state allows
the researchers to control the current passing through the
molecule.

Reed said, "It's like rolling a ball up and
over a hill, where the ball represents electrical current and the
height of the hill represents the molecule's different energy states.
We were able to adjust the height of the hill, allowing current to
get through when it was low, and stopping the current when it was
high."

The new breakthrough was possible by building on
research that Reed conducted in the 1990's that showed individual
molecules could be trapped between electrical contacts. The use of
molecules as transistors is very appealing because it is not feasible
at this time to create traditional transistors at such small
scales.

However, the researchers point out that functional
computers using the techniques are decades away. Reed said, "We're
not about to create the next generation of integrated circuits. But
after many years of work gearing up to this, we have fulfilled a
decade-long quest and shown that molecules can act as transistors."

"There is a single light of science, and to brighten it anywhere is to brighten it everywhere." -- Isaac Asimov